Description: (Taken Directly from the application) Absorptive hypercalciuria is a stone-forming condition in which hypercalciuria is believed to result from the primary enhancement of intestinal calcium absorption. Absorptive hypercalciuria is probably heterogeneous in origin, and may be broadly categorized into vitamin D-independent and vitamin D-dependent forms. Thus, besides recurrent nephrolithiasis, absorptive hypercalciuria is not known, but we have implicated a potential role of the catabolic skeletal effect of calcitriol excess. Therefore, since current long-term treatment is far from satisfactory, an ideal treatment should be one which produces a sustained correction of excessive intestinal absorption and renal excretion of calcium, and averts bone loss. This need has led to our hypothesis that a special formulation of orthophosphate (slow-release neutral potassium phosphate or UroPhos-K) would correct hypercalciuria, prevent recurrent stone formation and provide safety of usage in hypercalciuric nephrolithiasis due to absorptive hypercalciuria. In a controlled randomized trial, the effect of UroPhos-K will be compared with that of Urocit-K (potassium citrate) in hypercalciuric patients with absorptive hypercalciuria. The hypothesis to be tested is that UroPhos-K would lower urinary calcium unlike Urocit-K, and would be more effective than Urocit-K in inhibiting new stone formation. The safety and positive physicochemical and physiological effects of UroPhos-K in inhibiting new stone formation. The safety and positive physicochemical and physiological effects of UroPhos-K disclosed from ongoing long-term non-randomized trial provided the impetus to initiate this randomized trial.